You'll need to disassemble the drive to really find out if it is repairable. All I can provide is a little guidance.
These particular drives use an "Alps" mechanism, similar to those used in Commodore64 external drives and were half the height of the drives they superseded within the industry.
It's possible the part that you're looking at is the stepper motor drive band pulley tensioner (my description).
The stepper motor turns in accurate fine degrees, to which a metal band is attached. The metal band goes from the stepper motor, around a pulley and then attaches to the side of the head assembly. The band is tensioned by the pulley which is allowed to slide about a centimeter and tensioned with a spring to the main deck.
Once you get it disassembled take a pic and post it if you're not sure what your looking at.
Personally, I hated the Alps mechanism - especially when needing alignment.
This page details taking the covers off:
http://www.mushagaeshi.com/2015/05/17/repairing-apple-5-25-drive-a9m0107-for-apple-iigs/
Once there, you'll need to remove the two screws circled in red below, undo the read/write head cable, LED cable, disk and stepper motor cable to remove the upper board. Be careful with the read/write head cable - there is a small cable-tie to snip & the cable is very thin & delicate - pull via the connector rather than the cable.
WARNING, DO NOT undo any screws that have any kind of paint/epoxy (Glytpal) partially covering the screw head - those screws are alignment critical. Removing them means rendering the drive unusable without performing alignment.